These six volumes comprise the collected papers of Sir Harold Jeffreys from 1915 up to the present day. Edited by him, they have been carefully annotated in the light of later works. Sir Harold Jeffreys is probably best known for his work in geophysics - an interest that was aroused in his undergraduate days by Sir George Darwin's popular book on the tides - but his interests embrace a far wider field of study. This is shown particularly in the last volume, which includes, among other topics, his papers on probability and scientific method. Vol Theoretical and Observational Seismology Vol Observational Seismology Vol Gravity Vol Dissipation of Energy and Thermal History Vol Astronomy and Geophysics Vol Miscellaneous